Update/Add Readme.md files

[MadaZZ]

This is a helper repository. It contains multiple folders for a major topic. Add/Update the readme files for each folder adding more detail about the subject. Let's open-source. :)

PR Branch- Readmes-and-info

[sabiha22]

Can I work on this?

[MadaZZ]

@sabiha22 sure, go ahead! :)

[twentyonedot]

Can I work on this?
There is no readme file in the foundations folder.
I can write about hoisting.

[MadaZZ]

@twentyonedot A new readme will be a big task. That should include a lot of information about the general folder of the topic. The files must be listed and good use of markdown is a must. I hope you will do nicely. GO ahead! 🚀